The graphic arts industry is concerned with the matter of handling bundles of sheets, such as those coming from a conventional type of sheet stacker and with the sheets being bound into individual bundles of elongated shape, and stacking those bundles onto a horizontal surface, such as a pallet or table top or the like. U.S. Pat. No. 4,419,035, for instance, shows a method and apparatus utilizing an overhead crane for transporting bundles of sheets to a single location where the sheets are deposited onto a pallet. In that example, the bundles are all positioned in the same orientation, that is, with their longitudinal axis all being parallel and with the bundles being in side-by-side relationship and stacked upon each other to form various layers.
The present invention differs from the known prior art in that it provides a method and apparatus for stacking bundles in an interlocked relationship whereby the various bundles are stacked at two different orientations. That is, the longitudinal axis of some of the bundles are in one direction, and the longitudinal axis of others of the bundles are in a direction at right angles thereto. In that manner, the bundles are in an interlocked relationship and are therefore secure and sturdy in the stack and can be transported without having the bundles fall from a truck or other transport mechanism.
Still further, the apparatus and method of this invention provides for stacking the bundles in the secure relationship mentioned and to also provide for ready removal or unstacking, all in a convenient and efficient manner and in an automated system. Therefore, the bundles are neatly and quickly stacked in an automated manner, and they can also be quickly removed from the stack in automated manner.
Still further, the present invention provides apparatus and method for stacking bundles in a secure fashion and doing so in a manner which utilizes several transport mechanisms, such as a bundle transport overhead crane, so that the bundles can be stacked quickly and efficiently by the use of the several cranes or the like forming the bundles into one collection of several layers of the bundles.
It is also significant and important in this invention that the bundles can be unloaded from a pallet or table top or the like in an efficient and quick manner, in reverse procedure from the stacking or loading process.
In summary, the sheets, such as folded printed sheets of the graphic arts industry, are stacked and tied into bundles which are transported, such as by overhead cranes, to stacking stations where the bundles are laid in two different orientations in each layer of bundles, so that the stacked bundles are in a compact and secure stack.